


Playing With Matches

by Twelve (Dodici)



Category: Hunter X Hunter
Genre: M/M, all-powerful middle schoolers being their reckless selves, whale island, you could read it as friendship but Togashi would be disappointed
Language: English
Status: Completed
Published: 2020-03-29
Updated: 2020-03-29
Packaged: 2021-03-01 00:21:17
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,476
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23376058
Author URL: https://archiveofourown.org/users/Dodici/pseuds/Twelve
Summary: Gon is thirteen years old and indestructible—at least as long as Killua is willing to shoulder damage control, that is.
Relationships: Gon Freecs & Killua Zoldyck, Gon Freecs/Killua Zoldyck
Comments: 21
Kudos: 122





	Playing With Matches

**Author's Note:**

> It's social distancing day twenty here and the weather sucks, so please accept some silly adventure-y Whale Island vibes <3  
> It gets a bit claustrophobic in the middle, better approach with caution (also Gon is out of his mind and my English is weird, but what’s new XD).

It’s day seven of Killua sleeping on Gon’s bed and Whale Island has never looked so bright.

“Guess you two are out for lunch again?” aunt Mito asks, even if she isn’t exactly asking at all.

Gon grins.

“I want to show Killua the caves! He never went diving before,” he adds, looking at him because of course he never went freediving before, but it’s something that’s so fundamentally embedded inside Gon’s own memory that he can’t really wrap his mind around the concept.

“I live on a mountain. You’ve seen it,” Killua repeats, munching on his third helper of Abe’s most famous sponge cake – it’s been less than a week and she has already remade it in three different flavors just for him.

Mito is frowning.

“Wouldn’t that be dangerous?” she says, one eyebrow raised and looking at Killua like she’s sure he couldn’t possibly have the lung capacity to keep up with Gon.

“Diving is just swimming underwater, right? I can swim,” Killua says, looking at Gon.

“Well, you have to hold your breath. How long can you hold yours?”

“Oh, it depends on what I’m doing, I think? Like, in the worst set of circumstances I can hold it for twelve to fifteen minutes,” Killua says, still munching.

Gon blinks, trying to imagine what the worst set of circumstances could even be. He blinks again, numbers finally making sense inside his head. He doesn’t yell because Mito wouldn’t appreciate him yelling at the breakfast table.

“You are awesome, Killua! That’s a lot of time!”

“Is it?” he asks back, like he's never thought about it that way. “I’d usually get an earful if I could hold my breath only for that long… So it’s cool?”

He’s obviously asking if it’s okay for them to go diving, but when Gon answers he’s thinking about something else entirely.

“So cool,” he says, with admiration, and a weird prickling of bubbles right under his diaphragm. Killua goggles at him over the rim of a mug full of chocolate milk and Mito sighs hard in the background.

“Just try not to kill yourself,” she says, and Gon is pretty sure she’s talking mostly to him.

*

Killua can keep up with him no problem. Honestly, most of the time it’s the other way around: it’s Gon the one who asks himself if he could really keep up with Killua – who can jump so high and land on one foot like it’s nothing, who can climb on rocks no problem, hands buried inside his pockets. Gon asks about that too.

“It’s just a stupid habit,” Killua tells him. “You know, the only way to commit a perfect assassination is if the murder weapon doesn’t exist in the first place. But if the murder weapon is your hands, you better learn to keep them covered, especially if they get bloody or something.”

Gon thinks about it.

“Makes a lot of sense,” he decides in the end, and for some reason that comment seems to put Killua way more at ease. Gon too feels more at ease, because he’s getting to know Killua and every bit of information is convincing him that he likes him more than any other friends he’s ever had and not just because they’re the same age.

They get to the beach jumping down on the sandy slope, wind screaming inside their ears as they reach the rocky walls that wrap the cave's entrance from above, diving right inside crashing waves. The ocean is rough today, but the wind is cleaning up the sky, clouds wiped away in streaks.

Killua’s eyes are open wide with admiration when they start climbing – more like jumping – and the air becomes salty and wet, clinging at their clothes.

“Killua,” Gon calls, already removing his shirt. “Better leave everything here, we’ll get it back later.”

“It’s huge!” Killua says, still looking at the big, gaping mouth of the cave, growling as the water slams the walls full force, like the tail of a giant animal. 

“Told you,” Gon says, grinning. “We have to go a bit lower before we can enter, though. The sea bottom is actually pretty close.”

Killua rolls his eyes as fast as his head pops out of his shirt, hair disheveled and already damp.

“Yeah, don’t tell me how you managed to find that out.”

“I cracked my skull so hard aunt Mito wanted to call the helicopter to get me to the hospital,” Gon says, in a laugh.

“She should have, maybe you’ll be less of an idiot at this point—hey!”

Gon has jumped on him, using his head as a pivot while Killua’s arms were still trapped inside his shirt. He loses his pants on the way, grinning hard.

“Race you down!”

“Wait, it’s not fair!” Killua yells, but Gon is running already, using all the limbs that are not carrying the flashlight to get down.

He gets to the last biggest platform, a fairly wide stone smoothed by the ocean and the wind, scalding hot under his feet. Killua is right at his side once again, steps so light Gon didn’t even hear him follow. His underwear is way less flashy than Gon’s frog-patterned trunk and he looks even more ghostly pale than usual out there in the sun.

“It doesn’t go that far,” Killua says, peeking inside the cave, over Gon’s shoulder.

“Not on this side… You’ll see,” Gon says and he can feel it again, that exciting twitch inside his stomach, like popping bubble wrap against his ribcage. He extends a hand, and Killua looks at it, surprised. He catches it nonetheless and jumps when Gon says to jump; they fall, screaming until all sounds get swallowed up like their own bodies, chomped inside the cold, brains freezing and eyes open wide.

Killua’s hair is all up. He grins at Gon underwater until they’re both out, hair now flat on their head.

“Fuck, it’s cold,” Killua says, but he’s smiling so hard, voice loud over the coarse uproar of the water. He’s studying the ceiling from below as the waves push them toward the walls.

“Ready, now we go down,” Gon says, trying to steady his breath to get a good deal in. 

Killua nods. Gon counts to five with one hand raised and they’re gone, down below the surface, sound muted and pressure against the ears.

*

There are tunnels that stretch for meters under Whale Island. 

People come to visit, mostly during summer, and Gon has brought others there before. But never like this, no ropes, no gears, just him and Killua swimming fast around bulging, slimy rocks speckled with limpets, seaweed ticklish on their legs.

It’s a two minutes swim until Gon presses both feet on the ground to come up bouncing on the surface.

Killua is at his side in a blink, one hand to free his eyes from the hair.

“Wow, Gon,” he says, looking up at the sun. 

Gon may have planned it; there’s a time in the day when the sun is right above the round crevice and the light slides inside like snail slime, speckles of dust and salt glowing on the walls of the cavity.

Still, he didn’t plan for Killua’s face, the way the light rests on the bridge of his nose and the shadows of the plants living above draw floating shadows on his head; the way his eyes look like pools of sea themselves.

“What?” Killua asks, because Gon was staring of course. He can’t even feel properly sorry about it, because sometimes looking at Killua is like studying some kind of incredible wildlife and even better, Gon isn’t exactly sure. He’s just happy he gets so many chances. And maybe so many more now that Killua agreed to come searching for Ging with him.

He grins hard.

“Wanna do something fun?” he asks, excited. He really feels like he can do anything right now.

Killua blinks.

“Yeah. I mean, this is already pretty fun, but okay.”

Gon nods and starts swimming towards the darkest side of the cave, where the walls angle softly to dig shadowy crevices. The water is silent here, and quiet; Killua moves quietly in the water too, limbs barely moving and eyes curious.

“This isn’t the only tunnel,” Gon explains, and points below. “There’s another one that goes down for meters. We can explore!”

Killua looks down at their feet, where the tunnel starts. It’s engulfing water in long, cadenced gulps.

“Okay then. We just hold our breath?”

“Just that! And we try to swim fast.”

Killua shrugs.

“Okay then,” he says. “But don’t come back crying when I beat you!”

And he’s down already, leaving Gon scandalized as he inhales as much as he can, as fast as he can.

*

It becomes darker fast, and Gon flashes the torchlight up. Killua has actually waited for him, Gon should have known.

The tunnel is quite big, Gon has swum inside many times and can take the first turns blindfolded; that would be a pity, because there is an especially pretty carpet of algae there, dotted with puffed, colorful sponges bubbling from the ground up.

Killua is right behind him, keeping up at Gon’s pace no problem. Aunt Mito was worrying for no reason at all – but that’s okay, Gon sometimes forgets that not everybody knows how strong Killua is.

Here it comes, the point where the tunnel finally starts going up and the dark gets thicker and thicker. Gon is ready this time, he pushes faster with his legs—Killua catches his foot, and signs something, eyebrows scrunched.

Gon frowns and points up.

Killua points an index to his wrist, to sign an invisible clock.

Gon flashes a thumb up at his frown.

They swim for another couple of minutes – he’s never gone so far, the tunnel is narrowing now, and there aren’t any more seaweeds, but slimy rocks at arm's length, splotched with red algae; Gon grasps at some cracks to keep pushing forward.

This time Killua doesn’t grab his foot: he swims right in front of the flashlight and punches him on the shoulder – it’s way less painful than out of the water, but still a surprise.

He mouths something, but Gon can’t really understand what he’s trying to say over the screen of rising bubbles coming from his own nose. Killua signs five and then four with both hands, then up, then down.

Then… well, Gon really can’t understand him; even underwater he can hear him growl with frustration, though.

Gon points above. It’s going up, the tunnel. He’s sure he’s right. Seaweeds are starting to come back and he can already feel the pressure on his ears decreasing.

He doesn’t mouth words, he’s still trying to keep the air inside; Killua doesn’t seem bothered with that yet – he really is incredible. Gon has to discharge some more from his nose, bubbles climbing up until he pushes to swim past them.

His nostrils are burning up, a different kind of pressure than the one coming from outside; it’s a vacuum that’s starting to suck in. Gon grabs at another rock to rise faster. He can see it, the light at the end, the glint of the surface—or maybe those are Killua’s eyes, so blue and lit up with worry.

*

The light is up, somewhere behind his eyelids.

Gon coughs. It burns so much it’s like there are slimy electric eels inside his throat and up through his nose and down, curled up inside his lungs.

He coughs again, chest aching with every new breath. It hurts almost as much as having your ribs broken. 

There’s a sound wobbling around his head, something moving and some of that pressure doesn’t come from inside. It’s pretty outside-y. It’s someone slapping his face.

“Gon!” 

He opens one eye. He coughs again. Killua looks ready to choke him.

“Gon, I swear if you die I’m going to kill you!”

“That’s—” he tries. He coughs hard and messy; he tries again. “That’s impossible, Killua.”

“Just _try_ me,” he growls. There’s a halo of light around his damp head as he grabs Gon’s shoulders from above, eyes wild and _scared_. 

“Sorry,” he says then and he knows it’s the wrong answer way before Killua growls again and restrains to punch him just because he’s got both hands busy with helping him up. 

“Wow, I was right!” Gon says then, because his eyes are finally clear enough that the can take a look around. The tunnel has opened up in a wide cavity. There’s a big hole covered in greenery; the light comes from there, rays filtered by a thick blanket of plants. They’re on the forest side, someplace Gon has never seen before.

Killua hits him hard on the head. 

“Right about what,” he says, and he’s seething.

Gon tries to center himself, taking huge breaths in. They’re up on a rocky platform, surrounded by a forest of waterlilies, green and bronze leaves floating quietly just above the water.

“About the tunnel! I always found leaves and seeds and twigs that shouldn’t have been there on that side of the cliff, so I thought that the tunnel would lead somewhere inside the forest, and I was right!”

Killua is looking at him, silenced and still.

“You didn’t know?” he growls again, and hit him even harder than before. “What if it was a dead-end, then? We would have died!”

Gon tries to pick his head inside his hands, but his limbs are still wobbly and weak. He settles for smiling at Killua.

“But it wasn’t likely. I mean it’s pretty difficult for tunnels to be closed, water always finds a way to get out,” he says, and Killua hits him again on top of his head. He lets his fist rest there, as if he's deciding between ramming him unconscious or just pet his hair a bit.

“Yeah, and what if the exit was on the other side of the island? In such circumstances diving for more than half the time you can hold your breath is just stupid! You’ll need that time to come back if needed!”

Well, that’s right. Killua sure is amazing, he already knows all this stuff even if he never went diving before. Only… Gon tilts his head, tentatively, and raises both hands to stop another punch.

“But everything turned out alright in the end, doesn’t it?”

Killua too has raised his head, teeth gritted. He growls, deep and menacing, until he lowers both the fist and his head too, hair covering his face.

“Jeez, this is useless. Your head is too fucking hard, I give up.”

Gon isn’t sure if he should count it as a win, but he feels like grinning nonetheless.

*

Underwater the lilies look like giant eyelashes, flapping toward scant rays of sun coming from the eyehole of the cave’s entrance.

Gon lets himself float toward the surface and just stay there, waiting, until the fishes that started to gather around him run away in a swift of silver and Killua’s head springs out of the water, torchlight in hand.

“Found it,” he says, and Gon cheers.

“Thank you so much Killua! I would have been sad if I lost it, it's a present from Abe,” he says, and puts the string safely around his neck. 

“Next time don’t lose it like an idiot, then,” he hisses.

So, he’s still angry. 

Gon swims a bit toward the exit; the water isn’t any deeper than a mere puddle there, and fishes gather around his ankles. They may have never seen another human before; it’s quite an exciting thought.

“You know, Killua, this cave is basically unexplored, we may be the first people that has ever been here!” Gon says and Killua’s frown relaxes just a bit. Gon grins, he knew he could catch his interest. “Maybe Ging knew, aunt Mito told me he used to wander around the forest a lot, but still… See, I’ve never seen that plant before!” he adds, and he’s already jumping up, to get a better look at the hanging leaves, foiled crevices hiding purplish, juicy berries.

Gon climbs on the big, old trunk that’s fallen in a diagonal line almost inside the cave, edges ruined by what must have been a lightning. It’s a good spot; from there Gon can pick up a couple of berries and smell them—they fly up, his palm open, and when they fall there’s a much paler hand, swiping them away, fist closed.

The other fist falls on the top of Gon’s head.

“What were you doing, you idiot?”

Gon mumbles.

“What? Why Killua!” he yelps, more hurt by the gesture than the blow itself. “I was trying to smell them!”

Killua’s eyes narrow. He frowns and then opens up his palm again. 

“Oh. Go ahead then,” he says, and he’s already throwing the berries at him.

“Why—”

“I thought you would have eaten them! And we don’t know if they’re poisonous or…”

“I don’t think they are,” Gon says, pretty sure. “I can see some empty spots all around, so probably birds eat them all the time.”

They stay like that for a bit, Gon looking at the berries and Killua looking at Gon. Until he sighs, rolls his eyes and extends a hand.

“Well, come on, I know you’re dying to try it! Since you could die for real, better if I try it first.”

He’s already picked one berry from Gon’s hand. He studies it for a second before popping it inside his mouth like it was a jelly bean.

“Killua!”

“Calm down,” he says, and he’s already swallowed: he shows his tongue. It’s _blue_. “I’m immune to most poisons. So it’s pretty likely that, even if I’m not immune to this particular poison, I would still be able to make it through.”

Gon studies the remaining berry on his palm. He chomps it too, sweet and sour popping inside his mouth. His tongue prickles, it’s like eating unripe kiwis. 

“Gon, what the hell!” Killua is yelling again. “Spit it out!”

Gon looks at him and swallows.

“Is my tongue blue too?” he asks, as Killua gets white.

“Why did you do that! I told you—”

“I think it’s fine,” Gon says. “It’s unripe, but didn’t smell or taste bad, really. And I can’t make you risk alone!”

“I’m not risking anything, that’s the whole point!” Killua’s yell stops abruptly, like he’s realized something – something that angers him. 

“Whatever!” he yelps, and he’s already jumped, then, landing once again in the water with agility, lilies barely moving in his wake.

Gon stands there for a second, eyes still drawn toward the berries hanging from above. He has to shake his head.

“Hey, Killua! Wait for me!” he yells too, and makes his way from water to ground way more messily.

*

They start to get their way back throughout the forest. Killua is still angry, it's the third time his hands slid uselessly at his side as he fails to dig them inside nonexistent pockets.

Gon tries to cheer him up with a handful of berries.

“Some of these are good, the ones I took before were too sour,” he says, because he knows that Killua likes sweet flavors the most. He pops one between his teeth. Maybe those too will become blue. “Yeah, this one is almost as sweet as your nen aura! Do you think that aura flavor is somewhat linked to personality, like nen categories? It would make sense.”

Killua almost – almost – faceplants on a fern so big it looks like a palm tree.

He stands there, gawking at Gon with his mouth agape for an entire, long second before stomping away, ears red.

“First of all," he says, index raised. "I think that Hisoka is full of shit, that whole personality thing is way too vague to possibly be accurate. And, second, you don’t have any idea how embarrassing you are." He tells that in a growl, low and miserable. So much that Gon ends up feeling guilty.

“Why? Your aura is sweet,” he says, and he’s already jumping to keep up with Killua’s pace. “And it would make sense for every transmuter's aura to taste different, right? Like, I’m pretty sure Hisoka’s aura would taste weird, like garlic or something.”

“Like garlic,” Killua repeats, weirded out. He tilts his head while walking. Gon’s quick to get at his side and he can see it, the way his mouth curls up. Killua rolls his eyes and when he finally lets out a gruff laugh, Gon is already grinning from ear to ear. “Like garlic, really, that’s the best you can imagine.”

“I don’t know!” Gon says and they’re there once again, the bubbles inside his stomach, they always come back anytime he succeeds in making Killua smile. “I mean, I like garlic, but it’s also pretty strong and smelly and… Come on, Killua!” he says, and nudges him in the ribs with an elbow, since now Killua is laughing full-force. “What do _you_ think Hisoka’s aura tastes like, then?”

Killua’s eyes narrow, he taps on his chin with one finger.

“Maybe like one of those freakish sour candies, you know, the slimy, colorful ones.”

It’s a subject that keeps them entertained until they’re out of the forest, and the sound of the ocean is once again deafening loud.

“Let’s not talk about this ever again,” Killua says then, because Gon had started to propose that they should actually go ask Hisoka about it.

“But you’re not angry anymore, right?” he asks. Their clothes and shoes are when they left them. Gon should have known: Killua took the time to place weighty stones to prevent them from getting blown away by the wind. 

Killua puts his pants on with a frown, balanced on one foot.

“I wasn’t angry,” he says and then rolls his eyes because – Gon isn’t sure, probably his own expression. “I mean, I’m just… I know you enjoy the thrill or something, but you knew you couldn’t hold your breath that long, so why even try? And the stupid berries and—”

“So you didn’t have fun?” Gon asks, feeling a weird, unknown kind of churning inside his stomach. Did he mess up? He looks at the undone shoelaces on his boots. 

“That’s not—I just… I don’t get it, was it so important for you to beat me?” Killua says, eyes big and troubled. He looks like a moonbeam against rocks paler than him. “Holding your breath or eating poisonous stuff… I know how to hold my breath for so long because I trained for it, Gon, and it wasn’t—” he stops, face scrunching, thoughts gathering like a thunderous cloud. “It was training. It was useful but it wasn’t funny. It’s not a game, I didn’t want to hype you up or anything. I just told you what I could do, I didn’t mean for it to be harmful.”

The wind whips Gon in the face _hard_.

“It’s not like that,” he says, at Killua’s face, and at the whole cliff. And at himself, too, because maybe he is a bit reckless. Maybe he’s extremely reckless. And sometimes he feels the urge to put everything he’s got in everything they do, because he knows that Killua is stronger than him and smarter than him, and just plain incredible. But it’s never a competition, not with Killua: it’s with himself, to see how far he can go, to be as worthy as he can.

Maybe he didn’t really think things through as he should have. Like Killua always does, and that’s actually the point, right?

He jumps closer to Killua in one leap, pushing him toward the rocks and leaning on him in the process; he needs to look at him in the eyes and make stuff clear. 

“I’m serious, Killua!” he says. “The things you can do, I think they’re amazing! And that’s why… I wasn’t trying to beat you, I just didn’t think anything bad would happen to me, that’s all!”

Killua is taller than him, just that little bit that makes him crook his neck, a frown pressed deep between his eyebrows.

“That doesn’t make any sense, why—”

“And, don’t get mad, but I was kinda right, right?” Gon tries, tentatively, and it’s such a good thought, it just sounds right. “Nothing bad happened, because you were there.”

Killua being there, Killua having his back: Gon smiles at the concept, the bubbles are there once again – or maybe they’re butterflies? It’s this that people mean when they talk about having butterflies inside their stomach?

“I told you,” Gon insists, because Killua looks stunned, still only one arm inside his shirt, hair damp. “I never went exploring that tunnel because I was alone, but since you’re here now… I mean, I just thought that it would have been fine because you were there with me.”

“So you just assumed I would have somehow found a way to save your ass?” Killua says, face blank until he snaps. “You’re unbelievable.”

“But I was right,” Gon says, at the finger that’s tapping right between his eyes.

“Unbelievable!” Killua hisses, and maybe he’s even angrier now. Ops. “You’re such a moron! You’re telling me you do reckless stuff all the time because I’m here to avoid your death?”

Oh. Well. It sounds bad if it’s put like that.

“… Maybe?” 

Killua growls even harder.

“And that’s supposed to make me feel better? Man, you’re so selfish.”

“Yeah, I think I am,” Gon says, one hand on the nape of his neck. Killua is still shaking his head, putting on clothes like his socks are directly at fault for Gon’s recklessness. “But you have fun with me anyway, right Killua?” he asks, feeling silly because it’s not a rhetorical question: he wants to know it for real. He needs to know.

Killua sighs and plops down to put his shoes on.

“Yes, you moron,” he says then, face hidden by messy hair. “I told you already. I’ve fun when we’re together.”

Those butterflies, they’re _thriving_.

Gon steps inside his last boot in a single jump.

Killua raises his head, and Gon is already flashing him a blue tongue.

“Race you back home!” he says—yells, louder than the ocean.

He’s already running, then, and he knows. Some part of him knows that he’s walking on a thin line, that’s he’s challenging Killua’s patience and affection. It’s almost like he feels a dangerous need to find out how he can stretch that, how much he can ask out of him before Killua realizes how incredible he is—and how Gon is just Gon after all, and decides to leave him behind. 

For now, Killua is still right beside him, flashing him a tongue just as blue as his as they run, laughter overlapping in synch. 


End file.
